Textile heater



H. W. M CARD TEXTILE HEATER July 7, 1970' 3 She ets-Sheet 1 Filed Aug.12, 1968" r K ATTORNEYS July 7, 1970 H. w. MCCARD 3,518,322

TEXTILE HEATER Filed Aug. 12; 1968 s Sheets-Sheet 2 ATTORN EYS H. W. MCARD TEXTILE HEATER July 1, 1910 3 Sheets-Sheet 5 Filed Aug. 12, 1968I'NV ENTOR flea M4 4/4- 62ml BY M ATTORNEYS United States Patent "'ce3,518,822 TEXTILE HEATER Henry W. McCard, 208 Rodman Ave., Jenkintown,Pa. 19046 Filed Aug. 12, 1968, Ser. No. 751,785 Int. Cl. D01h 13/28;F2710 7/10 US. Cl. 57-34 15 Claims ABSTRACT OF THE DISCLOSUREDESCRIPTION OF INVENTION The present invention relates to textilemachinery for producing bulked synthetic thermoplastic contlnuousfilament yarn.

A purpose of the invention is to ply two ends of synthetic thermoplasticcontinuous filament yarn twisted with respect to one another, to bringthe plied yarn against the outside of a rotatable drum heater at aninlet end having a smooth cylindrical portion and carry the yarn in oneor more loops around the cylindrical portion, to carry the yarn in oneor more loops around a descending smooth conical portion to a takeo'tfend, the yarn being heated While on the drum to its thermoplastictemperature, to drop the yarn over a step at one or the other end of thesmooth conical portion, and then to cool the yarn to set it and separateit into bulked yarn ends.

A further purpose is to compensate for backup of twist from theseparating means toward the means for plying the yarn and allow forshrinkage by adjustment of the position of loops of yarn on the drum.

A further purpose is to guard against the danger of breakage of a pliedend on a drum heater by allowing for compensation of change in dimensioncaused by shrinkage or backup of twist.

A further purpose is to provide a heater drum which has sequentiallyencountered by the yarn a smooth cylindrical portion, an abruptdescending step, and a descending smooth tapering portion.

A further purpose is to provide a heater drum which has sequentiallyencountered by the yarn a smooth cylindrical portion, a smoothdescending conical portion, an abrupt descending step and then atakeofl? portion which may desirably be smooth and cylindrical.

A further purpose is to associate a heater drum having sequentiallyencountered by the yarn a smooth cylindrical portion and a descendingsmooth conical portion with a rotating pin around which the yarn passeswhich has a smooth cylindrical portion opposite the smooth cylindricalportion on the drum and which has a descending conical portion oppositethe descending conical portion on the drum.

A further purpose is to wrap the yarn in a plurality of loops around theheater drum and around a post or around 3,518,822 Patented July 7, 1970a plurality of posts, the post or posts or one of the posts being eithera fixed nonrotatable post or a post rotating around its own axis.

Further purposes appear in the specification and in the claims.

FIG. 1 is a diagram showing the complete textile operation of plying oftwo yarn ends twisted together, heating on the drum heater, cooling toset the bulk effect, and then deplying or separating the yarn ends andforming packages.

FIG. 2 is a side elevation of a preferred drum heater of the inventionpartially broken away to show one set of bearings.

FIG. 3 is a front elevation of the drum heater of FIG. 2.

FIG. 4 is an enlarged fragmentary axial section of the drum heater ofthe invention.

FIG. 5 is a side elevation similar to FIG. 2 of a modified heater drumof the invention showing also a rotating pin.

FIG. 6 is a front end elevation of the device of FIG. 5.

In the prior art numerous processes have been developed for creatingbulk and yarn stretch characteristics in synthetic thermoplasticcontinuous filament yarn such as nylon and the like. The problem isrendered difiicult by operation at higher and higher linear speeds,speeds of 40 yards per minute being now employed, and higher spindlespeeds sometimes as high as 150,000 r.p.rn.

Usually the creation of bulk and stretch characteristics involves acombination of heating and twisting and then cooling so that the effectofthe twist is set. Considerable use has been made of longitudinal orstrip heaters, but as linear speeds have increased these have tended tobecome longer, so that they are no longer convenient. Rotatable drumheaters have been developed, for example according to McCard and RossUS. patent application Ser. No. 580,978, filed Sept. 21, 1966, forRotating Drum Heater for Synthetic Yarn. This device conducts the yarnthrough channels on the surface of a drum.

Recently a duo-twist process has been adopted for creating bulk andstretch in thermoplastic continuous filament synthetic yarns, by whichtwo such yarn ends are twisted together to form a plied yarn, the pliedyarn is heated to render it thermoplastic and then cooled to set theyarn, and then the bulked yarn ends are separated and formed intopackages. See Carruthers US. Pat. No. 3,091,908, granted June 4, 1963.This process creates a problem if a prior art drum heater is used. Notonly does the yarn undergo shrinkage as in all similar cases, but thereis a pronounced tendency, even where adequate allowance is made forshrinkage on the drum heater, for the yarn to break on or adjacent tothe drum heater.

I have discovered that this breakage is due to the tendency of falsetwist to back up from the point at which the yarn ends are separatedtoward the point at which the plies are initially formed. I havediscovered that this breakage can be prevented by bringing the pliedyarn onto the heater drum on a smooth cylindrical preheating section andthen passes the yarn along a descending smooth conical portion. At oneor the other end of the smooth conical portion there is an abruptdescending step over which the yarn drops. One or more loops of yarn arewrapped around the cylindrical portion and one or more loops of yarn arewrapped around the conical portion and the yarn loops tend to adjusttheir positions along the axis of the drum as required to compensate forthe backup twist. Thus the yarn tends to stabilize its position as itpasses over the drum without undergoing such excessive loads thatbreakage occurs.

It is believed that the best application of the invention is likely tobe in creating nylon yarn with bulk and stretch characteristics fromcontinuous filament yarn usually having multifilarnents. For thispurpose the outside temperature of the drum should be approximately 400F., that is, in the range between 350 and 450 F.

The invention is also applicable to other continuous filamentthermoplastic yarns at appropriate temperatures for each of them, forexample polyester yarn, polyvinylchloride yarn, polyvinylchlorideacetate yarn, cellulose acetate yarn and polypropylene yarn.

The invention is intended to be applied to continuous filament syntheticthermoplastic yarn, examples being 70 denier, 34 filament nylon yarn and70 denier, 17 filament nylon yarn.

The broad concept of running yarn over a cone with takeoff at the smallend is old in Cadden U.S. Pat. No. 2,218,504, granted Oct. 22, 1940, andStanley U.S. Pat. No. 3,221,385, granted Dec. 7, 1965. Running yarn overa cane with takeolf at the large end is shown by Cotchett U.S. Pat. No.2,174,688, granted Oct. 3, 1939, and McCrosky U.S. Pat. No. 2,370,180,granted Feb. 27, 1945. None of these devices provides a cylindrical drumheater having a smooth cone descending from the cylinder to a takeoff atthe small end with an abrupt step at one or the other end of the smoothconical portion.

In one form of the invention which will first be described, the step isprovided at the point where the smooth cylindrical portion joins thedescending smooth conical portion. This will be described first afterwhich the description refers to a form in which the abrupt step is atthe small end of the smooth conical portion.

FIG. 1 illustrates diagrammatically equipment to which the invention isapplicable, this being for example a duotwist installation for creatingbulk and stretch characteristics in thermoplastic yarn such as nylon.

Yarn end 20 is withdrawn from a source 21 and passes through the hollowinterior of a stationary bobbin 22 supported at a point 23 near itsupper end. Another synthetic thermoplastic yarn end 24 is withdrawn froma source 25 and wrapped in a series of helical turns 26 around theoutside of the bobbin and then wrapped around the yarn end 20.

As the yarn end 20 advances, the yarn end 24 advances with it, pullingoff lower turns from the bobbin and at the same time more turns of yarnend 24 are formed toward the top of the bobbin, so that at a point 27each of the yarn ends 20 and 24 is plied together, being helically woundwith respect to the other yarn end, all as well known in the art.

The two-ply thermoplastic yarn 28 is brought into tangential contactwith the outside of a heater drum 30 according to the present inventionat its inlet end 31 and progresses along the drum to the takeoff end 32.

At the inlet end the yarn encounters a smooth outside cylindricalportion 33 which is of short extent since its main function is topreheat the thermoplastic yarn. Then the yarn encounters an abruptdescending step 34 which is placed approximately at the point whereextensive shrinkage occurs (nylon undergoes 14% shrinkage in thethermoplastic range). A step dimension of 0.05 inch on a side has beenfound to be adequate. Then follows a smooth gradual descending conicalportion 35 to the takeoff end 32. While various angles may be used onthis descending conical portion depending on the extent of backup oftwist to be compensated for, I find that the angle of the conicalportion should preferably be in the range from about to 25 and mostdesirably about 15 with respect to the axis of the drum.

Around the conical portion 35 of the drum there will suitably be fromthree to five or six loops 38 each of which in the preferred embodimentpasses around the outside of the post 37 as shown.

A rim 40 at the inlet end prevents the yarn from running off the drum atthat end and a rim 41 at the takeoff end prevents the possibility thatthe yarn will run off the drum at the other end.

In many installations the drum heater will provide all the heat that isnecessary, but in FIG. 1 I show an optional supplemental longitudinal orstrip heater 42 having a heating chamber 43 through which the plied yarnpasses.

From the heater or the last heater the plied yarn is guided over cantedrolls 44 and 45 so that it cools, while twisted, below the thermoplasticrange and is set in a stretch 46. The plied ends are then taken apart orseparated into bulked ends 47 and 48 having stretch characteristics andthese separate ends are run through guides 50 and 51 to form packages incontainers 52 and 53 as well known.

Thus the thermoplastic yarn ends 20 and 24 are first plied together andhelically wound about one another and then heat set and then deplied toform bulked and stretch-capable yarn ends 47 and 48.

As the heater drum operates in FIG. 1, the tension on the individualturn may vary and rather than breaking the loops, readjustment can takeplace by slipping of loops along the conical portion or failing to slipalong the conical portion and by pulling of loops from the cylindricalportion of the drum over the step. This effect varies with the extent towhich twist backs up onto the conical portion of the drum as a result ofthe twist introduced and the deplying action which separates the bulkedends. An equilibrium condition is reached between the tendency of thetwist to back up onto the cone and the tendency of the loops to slipalong the cone and thus the machine operates effectively at high speedswithout serious breakage.

The drum 30 as best seen in FIGS. 2 to 4 has a hollow interior 54 sothat it can surround a heater. A suitably hollow shaft 55 is journalledon antifriction bearings 56 mounted in a housing 57 which has a tubularbearing portion 58 and at the outer end is provided with a flange 60.The shaft has an opening 59 which permits air to circulate to cool thebearings. At one end of the shaft 55 there is provided a suitablyconical portion 61 which seats in a central conical opening 62 on thedrum and is held in place by a screw 63 threaded into the end of theshaft.

Depending on the installation, the drum may idle under the forwardmotion imparted by the takeup mechanism to the yarn by means not shown,or the shaft may be driven, suitably by a drive which has limited torquecapability such as a shaded pole electric motor so that the drum speedwill respond to variations in tendency of the yarn to move forward.

Within the hollow of the drum there is placed a heater, and while theheater can be a steam, hot air, or other suitable heater as desired, itis preferable to use an electric resistance heater. A suitable ceramicinsulator 64 has a hollow central opening 65 large enough to receive theshaft 55 with proper clearance, a shank portion 66 extending forwardwithin the hollow of the drum 30, and a flange portion 67 which extendsoutward against the flange of the housing and is anchored with thehousing by screws 68 extending into a mounting 70.

Around the ceramic shank 66 is mounted an electric resistance heater 72which is stationary within the drum 30 and is connected to a suitablesource of electric power as by leads 73.

At one position around the circumference adjacent the outside of thedrum 30 a guide post 37 is mounted by a screw 71 into the mounting 70.The guide post 37 may be wholly stationary or it may have a rotatablespool on the outside but in any case the post 37 has a fixed axis anddoes not revolve around the drum. The post may have a guide groove 69opposite the inlet point, but otherwise it is smooth to permit loops toslide axially.

In the form of the invention shown in FIGS. 5 and 6 the large end of thesmooth descending conical portion 35 adjoins the smooth cylindricalportion 33 and an abrupt descending step 34' is provided between thesmall end of the smooth conical portion 35 and a desirably smooth andcylindrical takeoff portion 70 adjoining the rim 41 at the small end.Thus, as shown in FIG. 5, the yarn 28 entering the heater drum passesaround the smooth cylindrical portion with at least a single turn, andthen has multiple turns, for example two or three, around the descendingconical portion before leaving the drum.

The yarn passes around the post 37 as previously de scribed on each ofits turns but in the form of FIGS. 5 and 6 each of the turns optionallyalso passes around a rotating pin 71 which is rotatably mounted on acenter shaft 72 by bearings not shown. The shaft 72 is supported on thebase. The rotating pin 71 has a flange 73 at the inlet end and then asmooth cylindrical portion 74 equal in length to the smooth cylindricalportion 33 on the drum. Then there is a smooth descending conicalportion 75 which is at least as long as the smooth descending conicalportion 35 on the drum, and which desirably continues to the takeoffflange 76.

The tapered portion of the rotating pin has a percentage reduction indiameter from the large end to the small end which is the same as thepercentage reduction in diameter of the conical portion of the drum.This feature permits the yarn to drive both the drum and the rotatingpin (assuming that they are driven by the yarn) without skiddingcircumferentially either on the rotating pin or on the drum.

While the process and device of the invention may employ wrapping ofeach loop around the drum and around a single post, it may also wrapeach loop around the drum and around two or more posts. The post or oneof the posts may be a nonrotatable post as in the form of FIGS. 1 to 4.The posts or one of the posts may be a rotatable or roller type post asshown in FIGS. 5 and 6.

In FIGS. 5 and 6 only one post may be used, and this may be either anonrotatable post or a rotatable post, or a plurality of posts may beemployed.

The presence of the step 34' at the outlet end in the form of FIGS. 5and 6 is favorable in a yarn where the shrinkage occurring on the drumdue to heat is more gradual than the shrinkage due to twist. By placingthis step 34 at the point where the twist shrinkage is more pronounced,the shock to the yarn from the twist shrinkage is less severe and thereis less likelihood of breakage.

The drum is made of a heat conducting metal, preferably aluminum alloy.It is preferable however to use a coating on the outside to guardagainst staining the yarn and this may be a cer-met coating which ispreferably of grey-black color so as to increase the emissivity from thestandpoint of heat transfer.

In operation two ends of thermoplastic continuous filament synetheticyarn are plied together so that each is twisted with respect to theother, and then the plied ends are passed in one or more loops aroundthe cylindrical preheating portion of the heater drum of the invention,passing around a guide post as part of each loop. At the place where themost pronounced shrinkage takes place the plied yarn falls over a step.If heat shrinkage is most severe the form of FIGS. 1 to 4 is preferredand if twist shrinkage is most severe, the form of FIGS. 5 and 6 ispreferable. Several loops of yarn are wrapped around the conicalportion, each loop at a part of its circumference passing over a guidepost and then the yarn is carried through a cooling stretch, after whichit is separated or deplied and the individual bulked yarn ends havingstretch characteristics are formed into packages.

Optionally there may be supplemental heating after passing through orover the heater drum.

On the heater drum of the invention, an adjustment takes place inrelative positions on the loops, brought about by backing up of twistfrom the point of separation of the bulked yarn ends having stretchcharacteristics to the heater drum, combined with the shrinkage effect,the adjustment being predominantly on the conical portion toward thetakeoff end of the drum.

In view of my invention and disclosure, variations and modifications tomeet individual whim or particular need will doubtless become evident toother skilled in the art to obtain all or part of the benefits of myinvention without copying the machine shown, and I, therefore, claim allsuch insofar as they fall within the reasonable spirit and scope of myclaims.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. In textile machinery, means for plying two ends of syntheticthermoplastic continuous filament yarn twisted with respect to oneanother, a rotatably mounted heater drum having an inlet end and atakeoif end, the drum having a smooth cylindrical portion at the inletend on which the plied yarn enters in contact with the outside of thedrum, a smooth descending conical portion toward the takeoff end fromwhich plied yarn leaves contact with the outside of the drum, a downwardstep at one end of the smooth conical portion, heater means inside thedrum, a guide post beside the drum around which the plied yarn iswrapped for part of eachturn, and means beyond the takeoff end of thedrum for separating the two yarn ends to produce bulked yarn, the yarnin turns wrapped around the drum compensating for backup of twist fromthe separating means toward the means for plying the yarn and allowingfor shrinkage of yarn.

2. A machine of claim 1, in which the downward step is located at thelarge end of the conical portion.

3. A machine of claim 1, in which the downward step is located at thesmall end of the conical portion.

4. A machine of claim 1, in which the post has a groove opposite thecylindrical portion of the drum.

5. A machine of claim 1, in which the post is nonrotatable.

6. A machine of claim 1 in which the post is rotatable.

7. A machine of claim 1, in which the post is rotatable on an axisparallel to the drum axis and around which the yarn is wrapped on eachturn, the rotatable post having a smooth cylindrical portion oppositethe smooth cylindrical portion on the drum and a descending smoothconical portion opposite the descending smooth conical portion on thedrum.

8. A machine of claim 5, in which on the smooth conical portion of therotating post the percentage of reduction in diameter is the same as onthe smooth conical portion on the drum.

9. In a heater for running lengths of yarn, a hollow heat conductivedrum having an inlet end and a takeoff end, the drum having at theoutside at the inlet end a smooth cylindrical portion, at the outsidetoward the takeoff end a smooth descending conical portion, an abruptdescending step at the outside at one end of the smooth conical portion,a shaft supporting the drum for rotation, bearings rotatably mountingthe shaft, a base supporting the bearings, a heater within the drum andaround the shaft, and a guide post beside the drum on the base.

10. A heater of claim 9, in which the abrupt descending step is at thelarge end of the conical portion.

11. A heater of claim 9, in which the abrupt descending step is at thesmall end of the conical portion.

12. A heater of claim 9, in which the post in nonrotatable.

13. A heater of claim 9, in which the post has a single groove oppositethe cylindrical portion.

14. A heater of claim 9, in which the post is rotatably disposed besidethe drum on an aXis parallel to the drum axis, having a smoothcylindrical portion opposite to the smooth cylindrical portion on thedrum and a smooth descending conical portion opposite the smoothdescending conical portion on the drum.

15. A heater of claim 14, in which the conical portion on the rotatingpost reduces in diameter by the same percentage as the conical portionon the drum.

References Cited UNITED STATES PATENTS 2,921,358 1/1960 Cox et a1.57--34 XR 3,018,608 1/1960 Kleekamm et al. 2871.3 XR

8 Carruthers 57-157 XR Burdge et a1. 219-469 Pettit 219-469 XR Seagrave219-469 XR Trifunovic et a1. 2871.3

MCCard et a1 2862 XR Berger 57-34 Hampel 57157 XR U.S. Cl. X.R.

